Hitherto, in an optical transmission apparatus that multiplexes optical signals through a transponder (WDM: Wavelength Division Multiplexing). The optical transmission apparatus has a monitoring unit that monitors operations of transponder units. The monitoring unit controls the optical transmission apparatus.
More specifically, the monitoring unit requests a provisioning and/or a controlling on the base of a control instruction (Control) to the optical transmission apparatus directly from user's operation or an NMS (Network Management System) indirectly through, for example.
The optical transmission apparatus notifies a user of information collection on alarming (e.g. Condition of System) and PM (Performance), for example, occurring in units therein. The monitoring unit and the transponder units have interfaces, respectively. The monitoring unit transmits the request by the user to the transponder units by the use of the interface. Moreover, the monitoring unit sends and receives information to the transponder units or from the transponder units.
For example, when the monitoring unit receives a setting request (Provisioning) or a control instruction (Control) from a user the monitoring unit notifies the target transponder unit of the request/instruction. The target transponder unit after the completion of the requested/instructed processing returns a request response/instruction response to the monitoring unit, and the monitoring unit notifies the processing result to the user.
Similarly, for the information collection on alarming and/or PM, the monitoring unit periodically notifies an information collection request to the transponder units. Each of the transponder units in response thereto collects information and notifies it to the monitoring unit. Then, the monitoring unit notifies the result of the information collection to a user as required.
However, in recent years, faster responses have been demanded to setting requests and control instructions from a user. There is a tendency that the amount of collection increases due to the increase in number of targets for information collection and the increase in the number of items. In particular, because a mesh configurable unit that directly communicates with an arbitrary transponder unit may further collect information on other units in addition to the own unit and notifies the result to the monitoring unit, the enormous amount of information is to be collected.
For those reasons, cases have occurred where the processing for a setting request or a control instruction from a user may delay due to the incompletion of the information collection processing. Because the amount of delay increases as the number of units increase, significantly large delay may occur in mesh-configurable units in which operations by multiple units are assumed.
Accordingly, a method has been conventionally applied including preparing a central monitoring system and collecting information by the central monitoring system, as illustrated in Japanese Laid-Open Patent Publication No. 06-164523, for decreasing the time for data collection by an intensive monitoring device.
However, with the prior art, though the data collection time between the intensive monitoring device and the central monitoring system decreases, the data collection time between NE (Network Equipment) and the central monitoring system does not decrease. Because the prior art is for a network of multiple NE, the central monitoring system may be deployed between the intensive monitoring device and the NE. However, the deployment of a system specially for information collection between a monitoring unit and a transponder unit may require an extra space, which is a problem.
In other words, in a case where multiple transponder units are still implemented in a mesh configuration at all times, the time for collecting information from transponder units by a monitoring unit increases. Therefore, the execution of a request or instruction with high priority by a user may be delayed by information collection processing with low priority, which is another problem.